Fewer teenagers are drinking regularly - partly because it is becoming harder for youngsters to get hold of alcohol, a Trading Standards survey suggests.

The number of those who say they never drink at all has climbed from 12% in 2005 to 17% in the latest poll, of 12,000 children in north-west England.

Those who drink regularly - at least once a week - fell from 50% to 44%.

However, a third of those who do drink do so to excess, and of those half admit to becoming violent while drunk.

The proportion of schoolchildren aged between 14 and 17 who bought their own alcohol dropped from 40% in the 2005 poll to 28%.

The Trading Standards Institute, which organised the survey in the north-west of England, said the results suggested a regime of more active policing of under-age alcohol sales was starting to work.

Changing attitudes

Professor Mark Bellis, Director of the Centre for Public Health, said: "It is very positive that we have seen such a dramatic drop in kids buying their own alcohol.

"But better regulation of under-age sales now needs to be matched by a culture change that will stop those children from wanting to buy alcohol in the first place, and that's something we're still not seeing."

Nearly 30% of those polled were managing to obtain and consume enough alcohol to be classified as binge drinkers - getting through five or more drinks in one sitting.

Better regulation of underage sales now needs to be matched by a culture change that will stop those children from wanting to buy alcohol in the first place

Prof Mark Bellis

Just over a quarter of binge drinkers said they had been in a car with a young person who had been drinking, and just over a fifth said they had regretted having sex while drunk.

The 2005 survey did not examine binge drinking, and so no figures were available for comparison, but experts say there is no evidence to suggest the problem is getting worse.

This year's survey also found that nearly 50% who drank alcohol claimed they drank at home when parents were in, or at functions with family and friends.

Earlier this year, the charity Alcohol Concern called for the prosecution of parents who gave alcohol to children, yet a subsequent study found those who drank with parental supervision were less likely to engage in binge drinking.